OnlyFm252
Active Directory Federation Services

CVE-2020-0837 — ADFS MFA Elevation of Privilege Vulnerability

Important CVSS 5 EPSS 0.01436 2020-09 archive

Executive Summary

An elevation of privilege vulnerability exists when Active Directory Federation Services (ADFS) improperly handles multi-factor authentication requests. An attacker who successfully exploited this vulnerability could bypass some, but not all, of the authentication factors. To exploit this vulnerability, an attacker could send a specially crafted authentication request. This security update corrects how ADFS handles multi-factor authentication requests.

Overview

5
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Elevation of Privilege
Released Sep 8 2020
Last Updated Sep 8 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.01436 — 0.69664 percentile
NVD CVSS 5 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
Low
INTEGRITY
Low
AVAILABILITY
Low
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 4.5

EPSS Score

0.01436
probability of exploitation in the next 30 days
0.69664 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

21 affected products
Product KB Article Severity Impact Restart Required
Windows 10 Version 1607 for 32-bit Systems 4577015 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1607 for x64-based Systems 4577015 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for 32-bit Systems 4570333 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for ARM64-based Systems 4570333 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for x64-based Systems 4570333 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1903 for 32-bit Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1903 for ARM64-based Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1903 for x64-based Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for 32-bit Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for ARM64-based Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for x64-based Systems 4574727 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for 32-bit Systems 4571756 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for ARM64-based Systems 4571756 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for x64-based Systems 4571756 (Security Update) Important Elevation of Privilege Yes
Windows Server 2016 4577015 (Security Update) Important Elevation of Privilege Yes
Windows Server 2016 (Server Core installation) 4577015 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 4570333 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 (Server Core installation) 4570333 (Security Update) Important Elevation of Privilege Yes
Windows Server, version 1903 (Server Core installation) 4574727 (Security Update) Important Elevation of Privilege Yes
Windows Server, version 1909 (Server Core installation) 4574727 (Security Update) Important Elevation of Privilege Yes
Windows Server, version 2004 (Server Core installation) 4571756 (Security Update) Important Elevation of Privilege Yes

Patches

4 patches
Article Type Restart
4577015 Security Update Yes
4570333 Security Update Yes
4574727 Security Update Yes
4571756 Security Update Yes

Known Exploits

Acknowledgments

Christopher Currens

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